Castellan Crowe

"This sword should be used by a Daemon prince, but I'm using it as an oversized walking stick coz that's just how I (t)roll"

Castellan Garran Crowe is both Captain and Brotherhood Champion of the Purifiers of the Grey KnightsChapter of Space Marines. The Purifiers are a group of specialists that burn shit with their minds and are the purest-hearted of the Knights. Castellan Crowe, needless to say, is both of these things, as well as being one of the best swordsmen in the Grey Knights.

A daemon sword that mindfucked every other guy that had ever wielded it.

A daemon sword that corrupted three full sectors and required the entire Grey Knights Chapter to step in and stop it.

A daemon sword that actively tries to murder Crowe every time he wields it.

A daemon sword that has near-infinite power and might possibly be a God in its own right, just waiting to be unleashed... (THIS IS SO DEFINITELY NOT MALALRETCONNIAN HELL, RIGHT GUYS?)

But Crowe just uses it as a regular sword, because using that near-infinite power would corrupt him.

Somewhat surprisingly, this pleased many Writefags, most of whom had grown weary of the overused "evil-thing-Fucks up-and-corrupts-good-guy" trope and rather enjoy a more heroic take on it.

Also, barely enduring the influence of a single daemon weapon makes a lot more sense (and is a lot cooler than) not only surviving in the Warp, but actively destroying all the Chaos Gods' shit. than being able to stroll through the Warp unharmed, destroying things and killing daemons, without any of that shit actually happening for reals because it gets remade after the Draigo-Jack are done there - But then again, that is the Warp, so sense might not fair to judge upon.

Although, Especially in the 5th edition book Ward makes sure to note how Crowe is the purest Marine of the purestpurifier order of the purest space marines that are the Grey knights, so uhh, while a cool dude, even he is not safe from Ward taint.

7th Edition also adds and takes away from his sueness in equal measure by making the leader of the Purifier Order (where the purest of the pure are grouped) and making him the most likely guy to take the place of Kaldor Titanfucking Draigo, but he keeps refusing because he has a bigger job taking care of the extremely foul blade and trying to keep track of what it says so he might find that one golden nugget of truth amongst a sea of insults.

[[1]]: This plays every time he polishes his daemon blade. Not only is it called "Black Blade", it shifts from dark and gloomy to light in tone, and ends up like a conflict with a lot of energy... So it fits fucking great.